In a Long Term Evolution (LTE) system, a base station sends scheduling signaling such as downlink control information (DCI) to user equipment (UE) by using a physical downlink control channel (PDCCH), allocates a resource such as a time-frequency resource to the UE, and schedules data transmission of the UE. A conventional frame structure of the LTE system is: A length of one transmission time interval (TTI) is equal to a length of one subframe, and one subframe includes 14 orthogonal frequency division multiplexing (OFDM) symbols.
To satisfy a requirement of transmitting a service that is sporadic and that has a quite high requirement on a delay, a concept of a short TTI is introduced, a length of the short TTI is proposed to be one/two/three/four/seven OFDM symbols, and moreover, UE of the short TTI is also required to support a TTI of a conventional length. For the UE of the short TTI, this is related to switching between TTIs of different lengths. If physical layer signaling is used to perform flexible dynamic switching, TTIs of different lengths may overlap each other at a same moment. For example, when carried data is transmitted in a long TTI, a sporadic short TTI and the long TTI overlap each other; or retransmission of data carried in TTIs of different lengths occurs at a same moment, and consequently long and short TTIs overlap each other. For different UEs, first UE transmits data by using a resource allocated by a base station, a short TTI that is needed when second UE transmits a service that is sporadic and that has a quite high requirement on a delay and a long TTI occupied by the first UE may overlap each other, and the first UE and the second UE interfere with each other.
It is mentioned by Qualcomm in R1-160906 of the 3rd Generation Partnership Project (3GPP) that, if TTIs of different lengths overlap each other when UE performs uplink data transmission, a long TTI is partially released, so as to transmit data carried in a short TTI. However, the foregoing solution is applicable to only a case in which TTIs of different lengths of same UE overlap each other. When TTIs of different lengths between different UEs overlap each other, the overlapping is not learned between the UEs, and the UEs interfere with each other. Consequently, data transmission reliability is reduced.